Imaging apparatus having a lens device for a zooming control operation and the method of using the same

ABSTRACT

An object of the present invention is to suitably perform a zooming control operation in the case that a zoom ring is provided at a lens-side portion and zoom switches are provided at a camera-body-side portion of a lens-interchangeable video camera. To achieve this object, in the case-that no zoom lens stop request is provided from the camera-body-side portion, it is judged from information sent from the camera-body-side portion which of a tele direction and a wide direction the moving direction of the zoom lens group is. Moreover, when the zoom angle is not placed at a tele end or at a wide end, lenses are driven by calculating data for driving the lenses. Thereafter, tele information is set or cleared according to whether the zoom lens group is placed at the tele end. Subsequently, zoom-ring operating information is detected. The detected zoom-ring operating information is sent to the camera-body-side portion. Then, the zoom lens group is controlled by generating zooming control information at the camera-body-side portion according to the zoom-ring operating information and zoom-switch operating information.

This application is a continuation of prior application Ser. No.10/643,805, filed Aug. 18, 2003, which is in turn a divisionalapplication of Ser. No. 09/208,546, filed Dec. 9, 1998, to both of whichpriority under 35 U.S.C. §120 is claimed. This application claims abenefit of priority based on Japanese Patent Application No. 9-341363,filed on Dec. 11, 1997; No. 9-342756, filed Dec. 12, 1997; No. 9-342757,filed Dec. 12, 1997; and No. 9-342758, filed Dec. 12, 1997, each ofwhich is hereby incorporated by reference herein in its entirety as iffully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lens device having a zoom lens, animaging device equipped with this lens device and adapted to performelectronic zooming, an imaging system, a lens control system and acomputer readable storage medium.

2. Description of the Related Art

FIG. 4 is a block diagram showing the configuration of a conventionallens-interchangeable video camera. In this figure, reference numeral 100designates an interchangeable lens unit; and 200 a camera body unit towhich the interchangeable lens unit is detachably attached. In theinterchangeable lens unit 100, reference numeral 101 denotes a fixedfront lens group; 102 a variator or zoom lens group for zooming orchanging a magnification; 103 a fixed lens group; 104 a compensator orfocusing lens group for performing both functions of compensating andfocusing. These lens groups 101 to 104 constitute a lens system of innerfocusing type.

Reference numeral 106 designates a stepping motor for moving thevariator lens group 102; 108 a rotation shaft that is connected to agear 107 through the stepping motor 106 and has a screw; 109 a rack thatis movably mounted on the rotation shaft 108 and provided with thevariator lens group 102. Reference numeral 105 denotes a driver fordriving the stepping motor 106; and 110 a zoom encoder for detecting theposition of the variator lens group 102.

Reference numeral 112 designates a stepping motor for moving thecompensator lens group 104; 113 a rotation shaft that is directlyconnected to a stepping motor 112 and has a screw; 114 a rack that ismovably mounted on the rotation shaft 113 and provided with thecompensator lens group 104. Reference numeral 111 denotes a driver fordriving the stepping motor 112. Reference numeral 115 designates amicrocomputer (hereunder sometimes referred to as a lens microcomputer)that communicates with a microcomputer 208 of the camera body unit 200and controls each of the drivers 105 and 111 and receives positiondetection information from the zoom encoder 110

Further, in the camera body unit 200, reference numeral 201 denotes animager such as CCD; 202 CDS/AGC circuit for performing a correlateddouble sampling operation and an automatic gain control operation; 203A/D converter; 204 a signal processing circuit; 205 an enlargementprocessing circuit for performing electronic zooming; 206 a signalprocessing circuit; 207 D/A converter; 208 a microcomputer (hereundersometimes referred to as a camera microcomputer) for controlling theentire video camera and for communicating with the lens microcomputer115; 210 and 211 zoom switches for moving the variator lens group in atele or telephoto direction and a wide or wide-angle direction,respectively; 212 and 213 focus switches for moving a focus position toan infinite focus position and to a shortest focus position,respectively; and 209 a group of these switches.

Next, an operation of this video camera will be described hereinbelow.When the interchangeable lens unit 100 is attached to the camera bodyunit 200, electric power is supplied from the camera body unit 200 tothe interchangeable lens unit 100. Then, an image is formed on theimager 201 from light that comes from an object through the lens groups101 to 104. Video signals obtained by photoelectric conversion performedin the imager 201 are processed by the CDS/AGC circuit 202.Subsequently, the video signals are converted by the A/D converter 203into digital video signals which are then sent to the signal processingcircuit 204. After the signal processing circuit 204 gamma-corrects thedigital video signals, the enlargement processing circuit 205 performsenlargement processing (to be described later) on the gamma-correctedvideo signals. Further, the signal processing circuit 206 performsbalanced modulation on color signals. The processed signals areconverted by the D/A converter 207 into digital analog video signalswhich are then sent to VTR (not shown).

Next, operations of the lens microcomputer 115 and zooming and focusingoperations will be described hereinbelow. When the zooming or focusingoperation is designated, the lens microcomputer 115 determines therotation speed and direction of each of the motors 106 and 112 byexecuting programs. Further, the lens microcomputer 115 outputs controlsignals representing the determined rotation speed and direction, andcontrols the stepping motors 106 and 112 through the drivers 105 and111, respectively. Incidentally, regarding the zooming operation, thelens microcomputer 115 determines the rotation direction of the motor106 according to the states of the switches 210 and 211, which arerepresented by signals outputted from the camera microcomputer 208,respectively. Regarding the focusing operation, in the case of adjustingfocus by a manual operation, the rotation direction of the motor 112 isdetermined according to the states of the switches 212 and 213, whichare represented by signals sent from the camera microcomputer 208. Onthe other hand, in the case of adjusting focus by an autofocusing (AF)operation, the rotation direction of the motor 112 is determined byexecuting AF processing routine in the lens microcomputer 115.

Each of the motors 106 and 112 rotate by being controlled according tothe aforementioned control signals. Thus, the rotation shaft 108 rotatesthrough the gear 107. Moreover, the rotation shaft 113 rotates. Each ofthe racks 109 and 114 moves back and forth together with a correspondingone of the lens groups 102 and 104. Consequently, predetermined zoomedand focused conditions of the video camera are obtained.

Next, enlargement processing (namely, electronic zooming) to beperformed on an image in the enlargement processing circuit 205 byutilizing linear interpolation will be described hereinbelow.Enlargement processing is performed by operating the zoom switches 210and 211 by a cameraman. When an original image shown in the left sidepart of FIG. 5A is expanded into an enlarged image shown in theright-side part thereof, scan lines representing the original image areas illustrated in the left-side part of FIG. 5B, and scan linesrepresenting the enlarged image are as illustrated in the right-sidepart thereof. In this case, the scan lines, which represent the enlargedimage and are respectively indicated by dashed lines in the right-sidepart of FIG. 5B, are newly formed from the scan lines A to Frepresenting the original image shown in the-left-side part thereof.Thus, each of the scan lines respectively indicated by dashed lines isobtained by multiplying data representing corresponding ones of scanlines, which are respectively indicated by solid lines in the right-sidepart of FIG. 5B, by weight factors (or correction coefficients)corresponding to the distances thereof and adding up resultant data. Theoriginal image can be enlarged at an arbitrary enlargement magnificationby performing such linear interpolation processing in the vertical andhorizontal directions.

FIG. 6 shows the configuration of the enlargement processing circuit205. For simplicity of description, this figure illustrates only thevertical enlargement processing. As shown in FIG. 6, input video signals300 are stored in a memory circuit 301 under the control of a memorycontrol signal generating circuit 302. Microcomputer interface circuit304 receives an enlargement magnification and enlargement informationfrom the camera microcomputer 208. Based on this, an enlargedmagnification determining circuit 303 outputs the enlargementmagnification to the memory control signal generating circuit 302 and aninterpolation coefficient generating circuit 308. The memory controlsignal generating circuit 302 reads signals, which respectivelyrepresent an nth line and an (n−1)th line delayed by 1 H (namely, onehorizontal scanning interval) from the nth line, from the memory circuit301. The interpolation coefficient generating circuit 308 generatesinterpolation coefficients corresponding to the enlargementmagnification and gives the generated interpolation coefficients tomultipliers 305 and 306. These multipliers multiply the signals, whichrespectively represent an nth line and an (n−1)th line, by theinterpolation coefficients. Outputs of these multipliers are added up inan adder 307. Resultant signal is outputted therefrom as an output videosignal 310.

Next, processing to be performed in the camera microcomputer 208 will bedescribed with reference to a flowchart of FIG. 7. In step 401, theprocessing is started. Then, predetermined initialization is performedin step 402. Subsequently, in step 403, the camera microcomputer 208waits for a vertical synchronization signal Vd. When the verticalsynchronization signal Vd is inputted to the camera microcomputer 208,control proceeds to step 404 whereupon the camera microcomputer 208makes predetermined communication with the lens microcomputer 115.Thereafter, the camera microcomputer 208 performs AF operation and anautomatic exposure (AE) operation in step 405. Then, the cameramicrocomputer 208 performs electronic and optical zooming in step 406.Subsequently, control returns to step 403.

FIG. 8 is a flowchart illustrating the operation performed in theaforementioned step 404 in more detail. As illustrated in FIG. 8, theoperation is started in step 501. Then, the camera microcomputer 208sends a communication request signal to the lens microcomputer 115 instep 502. Subsequently, control advances to step 503 whereupon thecamera microcomputer 208 checks whether a communication enabling signalcomes thereto from the lens microcomputer 115. If so, control proceedsto step 505. If not, control advances to step 504 whereupon the cameramicrocomputer 208 waits for a communication enabling signal for apredetermined time. If no communication enabling signal comes theretowithin the predetermined time, the camera microcomputer 208 gives upcommunicating with the lens microcomputer 115. Then, the cameramicrocomputer 208 finishes the communicating operation in step 506.

In the case that a communication enabling signals comes thereto withinthe predetermined time, bidirectional communication between the cameramicrocomputer 208 and the lens microcomputer 115 is performed in step505. At that time, data sent from the camera microcomputer 208 to thelens microcomputer 115 includes information on the halt or movingdirection of the zoom lens group, which is obtained as a result of theoperation performed in the aforementioned step 406. Further, data sentto the camera microcomputer 208 from the lens microcomputer 115 includesinformation on the inhibition/permission of electronic zooming.Subsequently, the camera microcomputer 208 terminates the communicatingoperation in step 506. Then, in step 507, control returns to theaforementioned step 406.

Next, the step 406 will be described in detail with reference to aflowchart of FIG. 9. As shown in FIG. 9, an operation is started in step601. Then, in step 602, the camera microcomputer 208 checks whether thecamera is performing zooming. When both the zoom switches 210 and 211are pushed, or when neither of the zoom switches 210 and 211 is pushed,control proceeds to step 607. When only one of the zoom switches 210 and211 is pushed, control proceeds to step 603 whereupon it is checkedwhich of the zoom switches 210 and 211 is pushed. If the “TELE” switch210 is pushed, control advances to step 604. If the “WIDE” switch 211 ispushed, control proceeds to step 608.

In step 604, the camera microcomputer 208 checks whether electroniczooming permission information comes thereto from the lens microcomputer115. If the camera microcomputer 208 is permitted to perform electroniczooming, control advances to step 605. If not, control proceeds to step610. In step 605, the camera microcomputer 208 checks whether the zoomlens group 102 is placed at a tele end. If so, control advances to step607. Otherwise, control proceeds to step 606 whereupon an electroniczooming operation is performed by increasing or decreasing theaforementioned interpolation coefficients according to which of theswitches 210 and 211, and whereupon the camera microcomputer 208controls the enlargement processing circuit 205 according to a result ofthe zooming operation. Upon completion of this control operation, thecamera microcomputer 208 sends a zoom lens stop request signal to thelens microcomputer 115 in step 607. Further, in step 610, the cameramicrocomputer 208 sends the lens microcomputer 115 a request to move thezoom lens group to the tele side.

On the other hand, in step 608, the camera microcomputer 208 checkswhether the camera is now performing electronic zooming. If so, controlproceeds to step 606. Otherwise, control advances to step 609 whereuponthe camera microcomputer 208 sends the lens microcomputer 115 a requestto move the zoom lens group to a wide side. Upon completion of theoperation to be performed in one of the aforementioned steps 607, 609and 610, control returns to a main routine in step 611.

FIG. 10 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. As illustrated in FIG. 10, the processing isstarted in step 701. Then, in step 702, the lens microcomputer 115checks whether the aforementioned zoom lens stop request signal comesthereto from the camera microcomputer 208. If so, namely, if the zoomlens group should be stopped, control proceeds to step 708. Otherwise,control advances to step 703 whereupon the lens microcomputer 115 checksaccording to the information sent by the camera microcomputer 208 whichof the tele direction and the wide direction the moving direction of thezoom lens group is. If the moving direction of the zoom lens group isthe tele direction, control proceeds to step 704. If the wide direction,control advances to step 705.

In step 704, the lens microcomputer 115 checks whether the zoom lensgroup is positioned at the tele end. If so, control proceeds to step708. Otherwise, control advances to step 706. Further, in step 705, thelens microcomputer 115 checks whether the zoom lens group is positionedat the wide end. If so, control proceeds to step 708. Otherwise, controladvances to step 706. The moving speed of the zoom lens group and themoving speed and direction of the focusing lens group are calculated instep 706. According to a result of this calculation, the zoom lens groupand the focusing lens group are driven in step 707. Furthermore, in step708, the zoom lens group is stopped.

Upon completion of the operation performed in step 707 or 708, the lensmicrocomputer 115 checks in step 709 whether the zoom lens group isplaced at the tele end. If so, control proceeds to step 710. Otherwise,control advances to step 711. In step 710, the lens microcomputer 115sends the camera microcomputer 208 an electronic zooming enablingsignal. Further, in step 711, the lens microcomputer 115 sends thecamera microcomputer 208 an electronic zooming inhibiting signal. Uponcompletion of the operation performed in step 710 or 711, controlreturns to the main routine in step 712.

As described above, in the case that the zoom switches 210 and 211 areprovided only in the camera body unit 200, optical zooming andelectronic zooming are realized under the control of the cameramicrocomputer 208. However, in the case that a zoom ring 116 to be usedfor manually performing a zooming operation is provided in theinterchangeable lens unit 100 as illustrated in FIG. 3, the conventionalvideo camera has the problem that it is difficult to achieve suitableand smooth control of optical zooming and electronic zooming.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to solve theaforesaid problem, thereby achieving suitable control of zoomingoperations in the case that zooming operation means are provided at bothcamera-body-side and lens-side portions, respectively.

Further, another object of the present invention is to smoothly switchbetween an optical zooming function and an electronic zooming function.

Moreover, still another object of the present invention is to enable anelectronic zooming function independent of whether a zooming mechanismis provided in a lens-side portion.

To solve the aforementioned problem and to achieve the foregoingobjects, according to an aspect of the present invention, there isprovided a lens device which comprises variator lens means forperforming a zooming operation, zoom operating means for operating theaforesaid variator lens means, information output-means for outputtingoperation information sent from the aforesaid zoom operating means andfor outputting zooming position information of the aforesaid variatorlens means, information input means for receiving control information,which is used for controlling the aforesaid variator lens means, from anexternal device, and variator control means for controlling a zoomingoperation of the aforesaid variator lens means according to the inputtedcontrol information.

Further, according to another aspect of the present invention, there isprovided an imaging apparatus which comprises imaging means for imagingan object and for *outputting an image signal, information input meansfor receiving external zoom operating information and zoom positioninformation to be supplied to external variator lens means, zoomoperating means for receiving internal zoom operating information to besupplied to the aforesaid external variator lens means and informationoutput means for generating and outputting optical zooming controlinformation to be used for controlling a zooming operation of theaforesaid external variator lens means according to the inputtedexternal zoom operating information and the inputted zoom positioninformation and the internal zoom operating information received fromthe aforesaid zoom operating means.

Moreover, according to still another aspect of the present invention,there is provided an imaging system that comprises a lens device havinga variator lens means for performing a zooming operation, lens-side zoomoperating means for operating the aforesaid variator lens means,lens-side information output means for outputting lens-side zoomoperating information and zoom position information on a zoom positionof the aforesaid variator lens means, which are received from theaforesaid lens-side zoom operating means, lens-side information inputmeans for receiving optical zoom control information to be used forcontrolling the aforesaid variator lens means, and variator controlmeans for controlling a zooming operation of the aforesaid variator lensmeans according to the received control information, and that furtherhas an imaging apparatus having imaging means for imaging an object andfor outputting an image signal, camera-body-side information input meansfor receiving the lens-side zoom operating information and zoom positioninformation from the aforesaid lens-side information output means,camera-body-side zoom operating means for receiving camera-body-sidezoom operating information to be supplied to the aforesaid variator lensmeans, and camera-body-side information output means for generatingoptical zooming control information to be used to control a zoomingoperation of the aforesaid variator lens means, according to thereceived lens-side zoom operating information and the received zoomposition information and the camera-body-side zoom operating informationand for outputting the optical zooming control information to theaforesaid lens-side information input means.

Furthermore, according to yet another aspect of the present invention,there is provided a computer readable storage medium for storing aprogram causing a computer to execute the steps of outputting operationinformation, which is obtained when a variator lens is operated, andzoom position information which represents a zoom position of theaforesaid variator lens, inputting control information, which is usedfor controlling the aforesaid variator lens, from an external device,and controlling the aforesaid variator lens according to the inputtedcontrol information.

Further, according to still another aspect of the present invention,there is provided a computer readable storage medium for storing aprogram causing a computer to execute the steps of imaging an object andoutputting an image signal, receiving external zoom operatinginformation and zoom position information to be supplied to an externalvariator lens, receiving internal zoom operating information to besupplied to the aforesaid external variator lens, and generating andoutputting optical zooming control information to be used forcontrolling a zooming operation of the aforesaid external variator lensaccording to the inputted external zoom operating information and theinputted zoom position information and the internal zoom operatinginformation.

Further, according to yet another aspect of the present invention, thereis provided a lens device which comprises variator lens means forperforming a zooming operation, zoom operating means for operating theaforesaid variator lens means, information output means for outputtingfirst zoom operating information, which is received from the aforesaidzoom operating means, and zoom position information representing a zoomposition of the aforesaid variator lens means, information input meansfor receiving second zoom operating information and zooming inhibitioninformation from an external device, and variator control means forcontrolling a zooming operation of the aforesaid variator lens meansaccording to the first zoom operating information, the inputted secondzoom operating information and the inputted zooming inhibitioninformation.

Moreover, according to still another aspect of the present invention,there is provided a camera apparatus which comprises imaging means forimaging an object and for outputting an image signal, information inputmeans for receiving first zoom operating information and zoom positioninformation to be supplied to external variator lens means, zoomoperating means for receiving second zoom operating information to besupplied to the aforesaid external variator lens means, informationoutput means for outputting the second zooming control information andoptical zooming inhibition information to be used for inhibiting azooming operation of the aforesaid external variator lens means,electronic zooming means for performing electronic enlargementprocessing on an image represented by the image signal, and electroniczooming control means for controlling the aforesaid electronic zoomingmeans according to the first zoom operating information, the zoomposition information and the second zoom operating information.

Furthermore, according to yet another aspect of the present invention,there is provided a camera system which comprises a lens device having avariator lens means for performing a zooming operation, lens-side zoomoperating means for operating the aforesaid variator lens means,lens-side information output means for outputting first zoom operatinginformation, which is received from the aforesaid lens-side zoomoperating means, and zoom position information on a zoom position of theaforesaid variator lens means, lens-side information input means forreceiving second zoom operating information and zooming inhibitioninformation from an external device and variator control means forcontrolling a zooming operation of the aforesaid variator lens meansaccording to the received second zoom operating information and thezooming inhibition information and the first zoom operating information,and further comprises an imaging apparatus having imaging means forimaging an object and for outputting an image signal, camera-body-sideinformation input means for receiving the first zoom operatinginformation and zoom position information from the aforesaid lens-sideinformation output means, camera-body-side zoom operating means forreceiving the second zoom operating information to be supplied to theaforesaid variator lens means, and camera-body-side information outputmeans for outputting the aforesaid lens-side information input means thesecond zoom operating information and the optical zooming inhibitionwhich is used for inhibiting the aforesaid variator lens means fromperforming a zooming operation, electronic zooming means for performingelectronic enlargement processing on an image represented by the imagesignal, and electronic zooming control means for controlling theaforesaid electronic zooming means according to the first zoom operatinginformation, the zoom position information and the second zoom operatinginformation.

Further, according to still another aspect of the present invention,there is provided a computer readable storage medium for storing aprogram causing a computer to execute the steps of outputting first zoomoperating information, which is obtained when a variator lens isoperated, and zoom position information which represents a zoom positionof the aforesaid variator lens, inputting second zoom operatinginformation and zooming inhibition information, which are received froman external device, and controlling the aforesaid variator lensaccording to the inputted second zoom operating information, theinputted zooming inhibition information and the first zoom operatinginformation.

Moreover, according to yet another aspect of the present invention,there is provided a computer readable storage medium for storing aprogram causing a computer to execute the steps of imaging an object andoutputting an image signal, receiving first zoom operating informationand zoom position information to be supplied to an external variatorlens, receiving second zoom operating information to be supplied to theaforesaid external variator lens, outputting the second zooming controlinformation and optical zooming inhibition information to be used forinhibiting the aforesaid external variator lens from performing azooming operation, and performing electronic zooming for electronicallyenlarging an image represented by the image signal according to thefirst zoom operating information and the second zoom operatinginformation and the zoom position information.

Furthermore, according to still another aspect of the present invention,there is provided a lens control system which comprises a first devicehaving optical variator means for optically changing a magnification ofan image, a second device having electronic variator means forelectronically enlarging an image by signal processing, and first andsecond variator operating members respectively provided in the aforesaidfirst and second devices. In this lens control system, when theaforesaid optical variator means is operated, the aforesaid opticalvariator means is controlled in the aforesaid first device according toinformation for operating the aforesaid first and second variatoroperating members. Further, when the aforesaid electronic variator meansis operated, the aforesaid electronic variator means is controlled inthe aforesaid second device according to information for operating theaforesaid first and second variator operating members. Furthermore,during the aforesaid electronic variator means is operated, theaforesaid first device inhibits the aforesaid optical variator meansfrom operating.

Further, according to yet another aspect of the present invention, thereis provided a camera system which comprises a lens device having anoptical variator lens for optically changing a magnification of animage, a camera device having electronic variator means forelectronically enlarging an image by signal processing, alens-device-side variator operating member, and a camera-device-sidevariator operating member. In this camera system, when the aforesaidoptical variator lens is operated, the aforesaid optical variator lensis controlled in the aforesaid lens device according to information foroperating the aforesaid lens-device-side and camera-device-side variatoroperating members. Further, when the aforesaid electronic variator meansis operated, the aforesaid electronic variator means is controlled inthe aforesaid camera device according to information for operating theaforesaid lens-device-side and camera-device-side variator operatingmembers. Moreover, during the aforesaid electronic variator means isoperated, a signal causing the aforesaid lens device to inhibit theaforesaid optical variator lens from operating is transmitted to theaforesaid lens device.

Furthermore, according to still another aspect of the present invention,there is provided a lens device which comprises variator lens means forperforming a zooming operation, control means for controlling thezooming operation of the aforesaid variator lens means, and signaloutput means for outputting an electronic zooming enabling signal and anelectronic zooming preparation signal for giving advance notice of theelectric zooming enabling signal, during the zooming operation.

Moreover, according to yet another aspect of the present invention,there is provided an imaging apparatus which comprises imaging means forimaging an object and for outputting an image signal, electronic zoomingmeans for electronically enlarging an image represented by the imagesignal, signal input means for receiving an electronic zoomingpreparation permission signal and an electronic zooming enabling signal,and control means for enabling control of the aforesaid electroniczooming means when each of the electronic zooming preparation permissionsignal and the electronic zooming enabling signal is received.

Further, according to still another aspect of the present invention,there is provided an imaging system which comprises a lens device havinga variator lens means for performing a zooming operation, first controlmeans for controlling the zooming operation of the aforesaid variatorlens means, and signal output means for outputting an electronic zoomingenabling signal and an electronic zooming preparation permission signalwhich gives advance notice of the electric zooming enabling signal,during the zooming operation, and which further comprises an imagingapparatus having imaging means for imaging an object and for outputtingan image signal, electronic zooming means for performing electronicenlargement processing on an image represented by the image signal,signal input means for receiving an electronic zooming preparationpermission signal and an electronic zooming enabling signal, and secondcontrol means for enabling control of the aforesaid electronic zoomingmeans when each of the electronic zooming preparation permission signaland the electronic zooming enabling signal is received.

Furthermore, according to yet another aspect of the present invention,there is provided a computer readable storage medium for storing aprogram causing a computer to execute the steps of controlling a zoomingoperation performed by a variator lens, and outputting an electroniczooming enabling signal and an electronic zooming preparation permissionsignal which gives advance notice of the electric zooming enablingsignal, during the zooming operation.

Moreover, according to still another aspect of the present invention,there is provided a computer readable storage medium for storing aprogram causing a computer to execute the steps of imaging an object andoutputting an image signal, performing electronic zooming forelectronically enlarging an image represented by the image signal,receiving an electronic zooming preparation permission signal and anelectronic zooming enabling signal, and enabling the electronic zoomingwhen each of the electronic zooming preparation permission signal andthe electronic zooming enabling signal is received.

Further, according to yet another aspect of the present invention, thereis provided an imaging apparatus which comprises imaging means,electronic zooming means for enlarging an image taken by the aforesaidimaging means, zoom input means for receiving zoom operatinginformation, lens information input means for receiving first zoominformation, which indicates presence or absence of an optical zoomingmechanism in an external lens means, and second zoom information whichindicates presence or absence of an optical zooming mechanism, whichdoes not operate in response to a control signal received from anexternal device, in the aforesaid external lens means, control outputmeans for outputting an optical zooming control signal which instructsthe aforesaid external lens means to perform a zooming operation andcontrol means for controlling the aforesaid optical zooming mechanism ofthe aforesaid external lens means through the aforesaid electroniczooming means and the aforesaid lens control output means according tothe zoom operating information inputted to the aforesaid zoom inputmeans in such a manner as to be able to be driven, in a case that thefirst zoom information indicates the presence of the aforesaid opticalzooming mechanism and that the second zoom information indicates theabsence of the aforesaid optical zooming mechanism, and for controllingthe aforesaid electronic zooming means in such a manner as to be able tobe driven, in a case that the first zoom information indicates theabsence of the aforesaid optical zooming mechanism, and for controllingthe aforesaid electronic zooming means in such a manner as not to bedriven, in a case that the second zoom information indicates thepresence of the aforesaid optical zooming mechanism.

Furthermore, according to still another aspect of the present invention,there is provided an imaging apparatus which comprises imaging means,electronic zooming means for enlarging an image taken by the aforesaidimaging means, zoom input means for receiving zoom operatinginformation, lens information input means for receiving zoominformation, which indicates presence or absence of an optical zoomingmechanism in an external lens means, and specific lens group informationwhich indicates whether the aforesaid external lens means belongs to aspecific lens group, control output means for outputting an opticalzooming control signal which instructs the aforesaid external lens meansto perform a zooming operation, and control means for controlling theaforesaid optical zooming mechanism of the aforesaid external lens meansthrough the aforesaid electronic zooming means and the aforesaid lenscontrol output means according to the zoom operating informationinputted to the aforesaid zoom input means in such a manner as to beable to be driven, in a case where the zoom information indicates thepresence of the aforesaid optical zooming mechanism and where thespecific lens group information indicates that the aforesaid externallens means does not belong to the aforesaid specific lens group, and forcontrolling the aforesaid electronic zooming means in such a manner asto be able to be driven, in a case where the zoom information indicatesthe absence of the aforesaid optical zooming mechanism, and forcontrolling the aforesaid electronic zooming means in such a manner asnot to be driven, in a case where the specific lens group informationindicates that the aforesaid external lens means belongs to theaforesaid specific lens group.

Other features, objects and advantages of the present invention willbecome apparent from the following description of preferred embodimentswith reference to the drawings in which like reference charactersdesignate like or corresponding parts throughout several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating processing concerning a zoomingoperation, which is performed by a lens microcomputer of a firstembodiment of the present invention;

FIG. 2 is a flowchart illustrating processing concerning a zoomingoperation, which is performed by a camera microcomputer of the firstembodiment of the present invention;

FIG. 3 is a block diagram showing the configuration of alens-interchangeable video camera according to the first embodiment ofthe present invention;

FIG. 4 is a block diagram showing the configuration of the conventionallens-interchangeable video camera;

FIGS. 5A and 5B are diagrams illustrating electronic zooming by theconventional video camera;

FIG. 6 is a block diagram showing the configuration of the enlargementprocessing circuit of the conventional video camera;

FIG. 7 is a flowchart illustrating the processing to be performed by thecamera microcomputer of the conventional video camera;

FIG. 8 is a flowchart illustrating the processing concerningcommunication to be performed by the camera microcomputer of theconventional video camera;

FIG. 9 is a flowchart illustrating the processing concerning zooming tobe performed by the camera microcomputer of the conventional videocamera;

FIG. 10 is a flowchart illustrating the processing concerning zooming tobe performed by the lens microcomputer of the conventional video camera;

FIG. 11 is a flowchart illustrating processing concerning zooming to beperformed by a lens microcomputer of a second embodiment of the presentinvention;

FIG. 12 is a flowchart illustrating processing concerning zooming to beperformed by a camera microcomputer of the second embodiment of thepresent invention;

FIG. 13 is a block diagram showing another example of the configurationof the enlargement processing circuit of the conventional video camera;

FIG. 14 is a diagram illustrating results of an actual zooming operationthat is conducted according to processing performed by lens and cameramicrocomputers of the second embodiment of the present invention;

FIG. 15 is a block diagram showing the configuration of alens-interchangeable video camera according to a third embodiment of thepresent invention;

FIG. 16 is a flowchart illustrating processing concerning a zoomingoperation, which is performed by a lens microcomputer of the thirdembodiment of the present invention;

FIG. 17 is a flowchart illustrating processing concerning a zoomingoperation, which is performed by a camera microcomputer of the thirdembodiment of the present invention;

FIG. 18 is a diagram illustrating results of an actual zooming operationthat is conducted according to processing performed by the lens andcamera microcomputers of the third embodiment of the present invention;

FIG. 19 is a diagram showing the configuration of an interchangeablelens unit;

FIG. 20 is a diagram showing the configuration of anotherinterchangeable lens unit;

FIG. 21 is a flowchart detailedly illustrating zooming processing to beperformed by a camera microcomputer of a fourth embodiment of thepresent invention;

FIG. 22 is a flowchart illustrating zooming processing to be performedby a camera microcomputer of the interchangeable lens unit of FIG. 19 inthe fourth embodiment of the present invention;

FIG. 23 is a flowchart illustrating zooming processing to be performedby a camera microcomputer of the interchangeable lens unit of FIG. 20 inthe fourth embodiment of the present invention;

FIG. 24 is a flowchart illustrating zooming processing to be performedby a camera microcomputer of the interchangeable lens unit of FIG. 4 inthe fourth embodiment of the present invention;

FIG. 25 is a flowchart detailedly illustrating zooming processing to beperformed by a camera microcomputer of a fifth embodiment of the presentinvention;

FIG. 26 is a flowchart illustrating zooming processing to be performedby the camera microcomputer of the interchangeable lens unit of FIG. 19in the fifth embodiment of the present invention;

FIG. 27 is a flowchart illustrating zooming processing to be performedby the camera microcomputer of the interchangeable lens unit of FIG. 20in the fifth embodiment of the present invention; and

FIG. 28 is a flowchart illustrating zooming processing to be performedby the camera microcomputer of the interchangeable lens unit of FIG. 4in the fifth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, the preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

First Embodiment

A lens-interchangeable video camera used for the first embodiment of thepresent invention is constituted as illustrated in FIG. 3. In FIGS. 3and 4, same reference numerals designate substantially the sameconstituent elements. Operating information of a zoom ring 116(lens-side zoom key information) is inputted to a lens microcomputer115. It is detected in the lens microcomputer 115 which of tele-side andwide-side zooming directions corresponds to a direction in which thezoom ring 116 is operated.

Further, a program for performing processing in the lens microcomputer115 according to the flowchart of FIG. 1 is stored in a storage medium117. Moreover, programs for performing processing in the cameramicrocomputer 208 according to the flowcharts of FIGS. 2, 7 and 8 arestored in a storage medium 214. Semiconductor memories, optical disks,magneto-optic disks or magnetic media may be used as these storage media117 and 214.

Next, processing to be performed by the lens microcomputer 115 of thefirst embodiment of the present invention will be described.

FIG. 1 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. In step 801, the processing is started.Then, in step 802, the lens microcomputer 115 checks whether a zoom lensstop request signal comes thereto from a camera microcomputer 208. Ifthe zoom lens stop request signal has already come thereto, controlproceeds to step 808. Otherwise, control advances to step 803 whereuponthe lens microcomputer 115 checks according to the information sent bythe camera microcomputer 208 which of the tele direction and the widedirection the moving direction of the zoom lens group is. If the movingdirection of the zoom lens group is the tele direction, control proceedsto step 804. If the wide direction, control advances to step 805.

In step 804, the lens microcomputer 115 checks whether the zoom lensgroup is positioned at the tele end. If so, control proceeds to step808. Otherwise, control advances to step 806. Further, in step 805, thelens microcomputer 115 checks whether the zoom lens group is positionedat the wide end. If so, control proceeds to step 808. Otherwise, controladvances to step 806. The moving speed of the zoom lens group and themoving speed and direction of the focusing lens group are calculated instep 806. According to a result of this calculation, the zoom lens groupand the focusing lens group are driven in step 807. Furthermore, in step808, the zoom lens group is stopped.

Upon completion of the operation performed in step 807 or 808, the lensmicrocomputer 115 checks in step 809 whether the zoom lens group isplaced at the tele end. If so, control proceeds to step 810. Otherwise,control advances to step 811. In step 810, the lens microcomputer 115sends the camera microcomputer 208 an electronic zooming enablingsignal. Further, in step 811, the lens microcomputer 115 sets opticaltele end information to be sent to the camera microcomputer 208. Then,control proceeds to step 812. Furthermore, in step 811, the lensmicrocomputer 115 clears optical tele end information to be sent to thecamera microcomputer 208. Then, control advances to step 812 whereuponthe lens microcomputer 115 detects the operating condition of the zoomring. Moreover, the lens microcomputer 115 provides a setting forsending the camera microcomputer 208 the lens-side zoom key informationindicating that the zoom ring 116 is not operated, or that the zoom ring116 is operated in a direction corresponding to the tele or wide side.Then, control proceeds to step 813. In this step, control returns to amain routine.

Next, processing to be performed in the camera microcomputer 208 of thefirst embodiment of the present invention will be described. The flow ofthe processing to be performed by the camera microcomputer 208 isbroadly similar to the flow illustrated in FIGS. 7 and 8.

Step 406 of a process flow of the camera microcomputer 208 will bedescribed in detail with reference to a flowchart of FIG. 2. In step901, the processing is started. Then, in step 902, the cameramicrocomputer 208 checks the lens-side zoom key information sent fromthe lens microcomputer 115. If the zoom ring 116 is not operated,control advances to step 903. Otherwise, control proceeds to step 904whereupon the camera microcomputer 208 further checks the lens-side zoomkey information sent from the lens microcomputer 115. If the zoom ring116 is operated in a direction corresponding to the tele side, controladvances to step 906. If the zoom ring 116 is operated in a directioncorresponding to the wide side, control proceeds to step 908. On theother hand, in step 905, the camera microcomputer 208 checks which ofthe switches 210 and 211 is pushed in the camera body unit 100. If the“TELE” switch 210 is pushed, control advances to step 906. Conversely,if the “WIDE” switch 211 is pushed, control proceeds to step 908.

In step 906, the camera microcomputer 208 judges from optical tele endinformation sent from the lens microcomputer 115 whether the zoom lensgroup is positioned at the optical tele end. If so, control advances tostep 907. Otherwise, control proceeds to step 910. Then, in step 907,the camera microcomputer 208 checks whether the zoom lens group isplaced at the tele end in the case of electronic zooming. If so, controladvances to step 911. Otherwise, control proceeds to step 909. On theother hand, in step 908, the camera microcomputer 208 checks whether anelectronic zooming operation is currently being performed. If so,control advances to step 909. Otherwise, control proceeds to step 912.

In this step 912, the camera microcomputer 208 establishes a setting forsending the lens microcomputer 115 a request signal to be used formoving the zoom lens group to the wide side. Further, in step 909, anelectronic zooming operation is performed by increasing or decreasingthe aforementioned interpolation coefficients according to which of theswitches 210 and 211 is pushed. Moreover, the camera microcomputer 208controls the enlargement processing circuit 205 according to a result ofthe electronic zooming operation. Then, control advances to step 911whereupon the camera microcomputer 208 provides a setting for sendingthe lens microcomputer 115 a zoom lens stop request signal. On the otherhand, the camera microcomputer 208 establishes a setting for sending thelens microcomputer 115 a request signal to be used for moving the zoomlens group to the tele side. Upon completion of the operation to beperformed in one of the aforementioned steps 910, 911 and 912, controlreturns to the main routine in step 913.

Incidentally, it has been described that this embodiment is adapted todetect the zoom operating direction (namely, detect that the zoom lensgroup is operated toward the tele side or toward the wide side).However, the present invention is easily applied to a case that thecamera has multi-zooming-speed in each zoom operating direction.

Further, even in the case that the camera body unit has a plurality ofzoom operating means or that an external input device, such as a remotecontrol device, for a camera body unit has zoom lens operating means,the present invention is easily applied to such a case by handling thesemeans as a single zoom operating means in the camera body unit.

As described above, according to the first embodiment, even if a zoomoperating means such as a zoom ring is provided therein, the operatinginformation and the zoom position information are outputted to anexternal camera. Moreover, a zooming operation is performed according tocontrol information provided by the camera. At that time, the controlinformation is generated in the camera body unit according to theoperating information, the zoom position information and zoom operatinginformation produced by a zooming operation of the camera body unit.Thus, even if the zoom operating means are provided in both the lensunit and the camera body unit, respectively, the camera smoothlyperforms suitable zooming control operations.

Furthermore, according to the first embodiment, the operatinginformation and the zoom position information are generated by a zoomingoperation of the lens unit and inputted to the camera body unit. Then,optical zooming control information is generated according to suchinputted information and internal zoom operating information produced bythe camera body unit. Subsequently, the optical zooming controlinformation is sent to the lens unit. Thus, even if the zoom operatingmeans are provided in both the lens unit and the camera body unit,respectively, the camera smoothly performs suitable zooming controloperations. Furthermore, the camera suitably performs electronic zoomingaccording to the aforementioned information.

Second Embodiment

A lens-interchangeable video camera used in this second embodiment isconstructed in such a manner as to be similar to the video camera usedin the first embodiment illustrated in FIG. 3. The video camera of thesecond embodiment is different from that of the first embodiment only inoperations thereof. Thus, only the difference therebetween will bedescribed.

In the case of a video camera in which a zoom ring 116 to be used formanually performing a zooming operation is provided in aninterchangeable lens unit 100 as shown in FIG. 3, an operating conditionthereof caused by switches is not uniquely determined. Thus, such avideo camera has the problem that it is difficult to achieve suitableand smooth control of optical and electronic zooming operations. Thesecond embodiment aims at solving this problem.

Hereinafter, the second embodiment will be described with reference tothe accompanying drawings.

In the case of the second embodiment, a program for performingprocessing, which includes an operation to be performed in the lensmicrocomputer 115 according to the flowchart of FIG. 11, is stored in astorage medium 117 shown in FIG. 3. Moreover, programs for performingprocessing in the camera microcomputer 208 according to the flowchartsof FIGS. 12, 7 and 8 are stored in a storage medium 214. Semiconductormemories, optical disks, magneto-optic disks or magnetic media may beused as these storage media 117 and 214.

Next, processing to be performed in the lens microcomputer 115 of thesecond embodiment of the present invention will be described.

FIG. 11 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. In step 1001, the processing is started.Then, in step 1002, the lens microcomputer 115 checks whether an opticalzooming inhibition signal comes thereto from a camera microcomputer 208.If the optical zooming inhibition signal has already come thereto,control proceeds to step 1009. Otherwise, control advances to step 1003whereupon the lens microcomputer 115 checks whether a zoom ring 110 ofthe interchangeable lens unit 100 is operated. If so, control proceedsto step 1006. Otherwise, control advances to step 1004.

In step 1004, the lens microcomputer 115 checks according to theinformation sent by the camera microcomputer 208 whether zoom switches210 and 211 of a camera body unit 200 are operated. If so, controlproceeds to step 1005. Otherwise, control advances to step 1009. In step1005, the lens microcomputer 115 judges from the information sent by thecamera microcomputer 208 which of the tele direction and the widedirection the operating direction in which the zoom lens group isoperated. If such an operating direction of the zoom lens group is thetele direction, control proceeds to step 1008. If the wide direction,control advances to step 1007. On the other hand, in step 1006, the lensmicrocomputer 115 judges which of the tele direction and the widedirection corresponds to the operating direction in which the zoom ring116 is operated. If such an operating direction of the zoom ring 116corresponds to the tele direction, control proceeds to step 1008. Ifcorresponding to the wide direction, control advances to step 1007.

In step 1008, the lens microcomputer 115 checks whether the zoom lensgroup is positioned at the tele end. If so, control proceeds to step1009. Otherwise, control advances to step 1010. Further, in step 1007,the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step 1009.Otherwise, control advances to step 1010. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step 1010. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in step 1011.

Furthermore, in step 1009, the zoom lens group is stopped.

Upon completion of the operation performed in step 1009 or 1011, thelens microcomputer 115 checks in step 1012 whether the zoom lens groupis placed at the tele end. If so, control proceeds to step 1013.Otherwise, control advances to step 1014. In step 1013, the lensmicrocomputer 115 sets optical tele end information to be sent to thecamera microcomputer 208. Then, control proceeds to step 1015.Furthermore, in step 1014, the lens microcomputer 115 clears opticaltele end information to be sent to the camera microcomputer 208. Then,control advances to step 1015 whereupon the lens microcomputer 115detects the operating condition of the zoom ring 116. Moreover, the lensmicrocomputer 115 provides a setting for sending the cameramicrocomputer 208 the lens-side zoom key information indicating that thezoom ring 116 is not operated, or that the zoom ring 116 is operated ina direction corresponding to the tele or wide side. Then, controlproceeds to step 1016. In this step, control returns to a main routine.

Next, processing to be performed in the camera microcomputer 208 of thesecond embodiment of the present invention will be described. The flowof the processing to be performed by the camera microcomputer 208 isbroadly similar to the flow illustrated in FIGS. 7 and 8.

Step 406 of a process flow of the camera microcomputer 208 will bedescribed in detail with reference to a flowchart of FIG. 12. In step1101, the processing is started. Then, in step 1102, the cameramicrocomputer 208 checks the zoom switches 210 and 211 of the camerabody unit 100. Further, the camera microcomputer 208 makes preparationsfor sending the lens microcomputer 115 a signal indicating that the zoomswitches 210 and 211 are not operated or that the zoom switches 210 and211 are operated in the tele or wide direction.

In step 1103, the camera microcomputer 208 checks the lens-side zoom keyinformation sent from the lens microcomputer 115. If the zoom ring 116is not operated, control advances to step 1104. Otherwise, controlproceeds to step 1105 whereupon the camera microcomputer 208 furtherchecks the lens-side zoom key information sent from the lensmicrocomputer 115. If the zoom ring 116 is operated in a directioncorresponding to the tele side, control advances to step 1107. If thezoom ring 116 is operated in a direction corresponding to the wide side,control proceeds to step 1109. On the other hand, in step 1104, thecamera microcomputer 208 checks whether the switches 210 and 211 arepushed in the camera body unit 100. If so, control advances to step1106. Otherwise, control proceeds to step 1111. In step 1106, the cameramicrocomputer 208 checks which of the switches 210 and 211 is pushed inthe camera body unit 100. If the “TELE” switch 210 is pushed, controladvances to step 1107. Conversely, if the “WIDE” switch 211 is pushed,control proceeds to step 1109.

In step 1107, the camera microcomputer 208 judges from optical tele endinformation sent from the lens microcomputer 115 whether the zoom lensgroup is positioned at the optical tele end. If so, control advances tostep 1108. Otherwise, control proceeds to step 1112. Then, in step 1108,the camera microcomputer 208 checks whether the zoom lens group isplaced at the tele end in the case of electronic zooming. If so, controladvances to step 1111. Otherwise, control proceeds to step 1110. On theother hand, in step 1109, the camera microcomputer 208 checks whether anelectronic zooming operation is currently being performed. If so,control advances to step 1110. Otherwise, control proceeds to step 1112.

In step 1110, an electronic zooming operation is performed by increasingor decreasing the aforementioned interpolation coefficients according towhich of the switches 210 and 211 is pushed. Moreover, the cameramicrocomputer 208 controls an enlargement processing circuit 205according to a result of the electronic zooming operation. Then, controladvances to step 1111 whereupon the camera microcomputer 208 provides asetting for sending the lens microcomputer 115 an optical zoominginhibition signal. Subsequently, control proceeds to step 1112 whereuponcontrol returns to the main routine.

Incidentally, it has been described that the second embodiment isadapted to detect the zoom operating direction (namely, detect that thezoom lens group is operated toward the tele side or toward the wideside). However, the present invention is easily applied to a case thatthe camera has multi-zooming-speed in each zoom operating direction.

Further, even in the case that the camera body unit has a plurality ofzoom operating means or that an external input device, such as a remotecontrol device, for a camera body unit has zoom lens operating means,the present invention is easily applied to such a case by handling thesemeans as a single zoom operating means in the camera body unit.

As described above, according to the second embodiment, even if a zoomoperating means such as a zoom ring is provided therein, a zoomingoperation is controlled in accordance with the corresponding firstoperating information and the zoom position information and the zoominginhibition information. At that time, a zooming operation is controlledby the camera body unit according to the first operating information,the zoom position information and second zoom operating informationproduced by a zooming operation of the camera body unit. Thus, even ifthe zoom operating means are provided in both the lens unit and thecamera body unit, respectively, the camera smoothly performs suitablezooming control operations.

Furthermore, according to the second embodiment, the first operatinginformation and the zoom position information are generated by a zoomingoperation of the lens unit and inputted to the camera body unit. Thus,an electronic zooming operation is performed according to such inputtedinformation and second zoom operating information produced by the camerabody unit. Moreover, the second zoom operating information and theoptical zooming control information are generated and sent to the lensunit. Thus, even if the zoom operating means are provided in both thelens unit and the camera body unit, respectively, the camera smoothlyperforms suitable zooming control operations.

Third Embodiment

Video cameras having both the optical zooming function and theelectronic zooming function, similarly as the first and secondembodiments, have the problem that it is difficult to smoothly switchbetween the optical zooming function and the electronic zoomingfunction. Hereinafter, this problem will be described by taking theconventional video camera shown in FIG. 4 as an example.

FIG. 13 shows the configuration of the enlargement processing circuit205 of the conventional video camera illustrated in FIG. 4. Forsimplicity of description, this figure illustrates only verticalenlargement processing.

As shown in FIG. 13, an input video signal 300 is stored in a memorycircuit 301 under the control of a memory control signal generatingcircuit 302 and sent to an output switch circuit 309. Microcomputerinterface circuit 304 receives an enlargement magnification andenlargement information from a camera microcomputer 208. Based on this,an enlarged magnification determining circuit 303 outputs theenlargement magnification to the memory control signal generatingcircuit 302 and an interpolation coefficient generating circuit 308. Thememory control signal generating circuit 302 reads signals, whichrespectively represent an nth line and an (n−1)th line delayed by 1 Hfrom the nth line, from the memory circuit 301. The interpolationcoefficient generating circuit 308 generates interpolation coefficientscorresponding to the enlargement magnification and gives the generatedinterpolation coefficients to multipliers 305 and 306. These multipliersmultiply the signals, which respectively represent an nth line and an(n−1)th line, by the interpolation coefficients. Outputs of thesemultipliers are added up in an adder 307. Resultant signal is outputtedtherefrom to the output switch circuit 309. Then, the output switchcircuit 309 outputs the signal sent from the adder 307 or the inputvideo signal 300 according to a switch signal sent from themicrocomputer interface circuit 304 as an output video signal 310.

However, in the conventional circuit, it is difficult to set the timingof the switching between optical zooming, which is performed in theinterchangeable lens unit, and enlargement processing which is performedby utilizing the electronic zooming in the camera body unit. Moreover,for some reason, the conventional circuit has no means (for example, aprocess sequence) for discontinuing the enlargement processing in thecamera body unit (for instance, in the case that the interchangeablelens unit has a zoom ring for mechanically moving the variator lens andthat a gear has a slip mechanism for transmitting the movement of thezoom ring to the rotation shaft, a cameraman operates the zoom ring in adirection corresponding to the wide side).

Thus, in Japanese Unexamined Patent Publication No. 9-96756 OfficialGazette, the inventors of the present invention have proposed devices tosolve the aforementioned problem. Consequently, smooth switching betweenoptical and electronic zooming operations is achieved. However,troubles, such as suspension of a zooming operation, may happen in thecases that a delay occurs in transmission of an electronic zoominginhibition or permission signal between the lens unit and the camerabody unit due to some cause and that, after an electronic zoomingenabling signal is received by the camera body unit, a delay occurstherein until electronic zooming is performed therein.

Hereinafter, this phenomenon will be described in detail.

FIG. 14 is a diagram illustrating the timing with which an output videosignal is changed from video signals of an optical zooming region tothose of an electronic zooming region when a zooming operation isperformed from the wide side to the tele side. In this diagram, thetransverse axis represents time. As viewed in this diagram, the righterthe position of a time point on the transverse axis becomes, the latertime the time point indicates.

In FIG. 14, reference numeral 801 denotes a row representing a sequenceof fields of a standard television signal. Fields (n−1) to (n+4) areshown in this figure. Reference numeral 802 designates a row showingvarious kinds of processing to be performed by the camera microcomputer208 in the respective fields. The aforementioned kinds of processingillustrated in FIG. 7 are performed in the respective fields. Referencenumeral 803 designates a row showing the field Nos. of fields in whichthe input video signals 300 are obtained by photoelectric conversion.Incidentally, a field, in which a video signal is read from an imager201, is just subsequent to a field in which this video signal isobtained by photoelectric conversion. Thus, the field No. of this fieldis smaller than the field No. thereof shown in the row 801 by 1.

Reference numeral 804 designates a row showing the field No. of a fieldin which an output signal of the adder 307 is obtained in the imager 201by photoelectric conversion. However, an output signal of the adder 307is indefinite until a video signal is fetched in the memory circuit 301.After a video signal is fetched thereto, a signal delayed by 1 field isoutputted from the adder 307. Reference numeral 805 denotes a rowindicating which of the input video signal 300 and the output signal ofthe adder 307 is selected by the output switch circuit 309 according toa switch signal outputted from the microcomputer interface circuit 304shown in FIG. 13. Reference numeral 806 designates a row indicating thefield No. of a field in which the output video signal 310 is obtained inthe imager 201 by photoelectric conversion.

Next, a process flow of the zooming processing will be described byconcentrating on the processing to be performed by the cameramicrocomputer 208.

During the zooming operation from the wide side to the tele side, thelens microcomputer 115 prepares electronic zooming permissioninformation for the next communication with the camera microcomputer 208in the field n when the optical zoom lens reaches the optical tele endat the time t(n) 1.

In the field (n+1), an electronic zooming enabling signal is sent fromthe lens microcomputer 115 to the camera microcomputer 208 by thecommunication performed at the time t(n)1. In the zooming processing atthe time t(n+1)2, the camera microcomputer 208 performs an operation forcausing the memory circuit 301 to store the input video signal in thetime (n+2).

In the field (n+2), an operation for causing the input video signal 300obtained in the field (n+3) to be stored in the memory circuit 301 isperformed. Moreover, operations of enlarging an image, which isrepresented by the stored input video signal 300 in the field (n+2), inthe field (n+3), and of outputting a video signal (n+1)′ representing anenlarged image, and of selecting a received output of the adder 307 asan output of the output switch circuit 309.

In the field (n+3), an operation of storing the input video signal 300,which is obtained in the field (n+4), in the memory circuit 301 isperformed during the zooming processing at the time t(n+3). Further, thecircuit performs operations of enlarging an image, which is representedby the stored input video signal 300 in the field (n+2), in the field(n+3), and of outputting a video signal (n+1)′ representing an enlargedimage, and of selecting a received output of the adder 307 as an outputof the output switch circuit 309. Further, the circuit performsoperations of enlarging an image, which is represented by the storedinput video signal 300 in the field (n+3), in the field (n+4), and ofoutputting a video signal (n+1)1 representing an enlarged image, and ofoutputting a video signal (n+2)′ to the output switch circuit 309. Inand after the field (n+4), the same processing as performed in the field(n+3) is carried out.

Next, change 806 in the output video signal 310 with time will bedescribed. Because the zoom lens reaches the optical tele end in thefield “n”, signals obtained in the imager 201 by photoelectricconversion in the fields up to (n−1) and signals obtained byphotoelectric conversion in the field “n”, in which the optical zoomingis ceased in the middle thereof, are video signals obtained during theoptical zooming. Thus, the output video signals outputted in the fieldsup to (n+1) are signals outputted during the optical zooming. Signalsobtained in the field (n+1) by photoelectric conversion are outputtedwithout change as the output video signal 310 in the field (n+2), andthus are neither signals obtained during the optical zooming, norsignals obtained during the electronic zooming. The output video signals310 outputted in the field (n+3) and the subsequent fields are obtainedby enlarging signals stored in the memory circuit 301 and are videosignals obtained during the electronic zooming.

As is understood from the foregoing description, the zooming issuspended in the case that a time lag occurs between the reception ofthe electronic zooming enabling signal and the implementing of theelectronic zooming in the camera body unit.

This third embodiment aims at solving the aforementioned problem and atachieving the smooth switching between the optical zooming and theelectronic zooming.

Hereinafter, the third embodiment will be described with reference tothe accompanying drawings.

A lens-interchangeable video camera used in the third embodiment isconstructed in such a manner as to be similar to the video camera usedin the first embodiment illustrated in FIG. 4. The video camera of thesecond embodiment is different from that of FIG. 4 only in that thevideo camera of this embodiment has storage media 117 and 214 asillustrated in FIG. 15. Further, the flow of the processing to beperformed by the camera microcomputer 208 is broadly similar to the flowillustrated in FIGS. 7 and 8.

Further, the storage medium 117 stores a program for performing aprocess illustrated in a flowchart of FIG. 16, which is executed by thelens microcomputer 115. Moreover, the storage medium 117 stores aprogram for performing processes illustrated in flowcharts of FIGS. 17,7 and 8, which are executed by the camera microcomputer 208.Semiconductor memories, optical disks, magneto-optic disks or magneticmedia may be used as these storage media 117 and 214.

First, step 406 of a process flow (see FIG. 7) by the cameramicrocomputer 208 of the third embodiment of the present invention willbe described in detail with reference to FIG. 17. Incidentally, in thefollowing description, it is assumed that only the zoom switches 210 and211 move the variator lens group 102.

As shown in FIG. 17, in step 1201, the processing is started. Then, instep 1202, the camera microcomputer 208 checks whether a zoomingoperation is being performed. Subsequently, if both the zoom switches210 and 211 are pushed, or if neither of these zoom switches is pushed,control advances to step 1207. If only one of these zoom switches ispushed, control proceeds to step 1203 whereupon the camera microcomputer208 further checks which of the switches 210 and 211 is pushed. If the“TELE” switch 210 is pushed, control advances to step 1204. If the“WIDE” switch 211 is pushed, control proceeds to step 1208.

In step 1204, the camera microcomputer 208 judges whether electroniczooming permission information comes thereto from the lens microcomputer115. If electronic zooming is permitted, control advances to step 1205.Otherwise, control proceeds to step 1210. In step 1205, the cameramicrocomputer 208 checks whether the zoom lens group is positioned atthe optical tele end. If so, control advances to step 1207. Otherwise,control proceeds to step 1206 whereupon an electronic zooming operationis performed by increasing or decreasing the aforementionedinterpolation coefficients according to which of the switches 210 and211 is pushed. Moreover, the camera microcomputer 208 controls theenlargement processing circuit 205 according to a result of theelectronic zooming operation. Then, in step 1207, the cameramicrocomputer 208 sends a zoom lens stop request signal to the lensmicrocomputer 115.

On the other hand, in step 1208, the camera microcomputer 208 checkswhether an electronic zooming operation is currently being performed. Ifso, control advances to step 1206. Otherwise, in step 1209, the cameramicrocomputer 208 sends the lens microcomputer 115 a request signal formoving the zoom lens group in a direction corresponding to the wideside.

Further, in step 1210, the camera microcomputer 208 checks whether anelectronic zooming preparation permission signal comes thereto from thelens microcomputer 115. If permitted, control advances to step 1211.Otherwise, control proceeds to step 1212. In step 1211, the cameramicrocomputer 208 makes preparations for starting the electroniczooming. Then, control advances to step 1212. Input image signal 300 isstored in the memory circuit 301 so that, owing to the preparations madein step 1211, an electronic zooming operation can be performedimmediately after an electronic zooming permission signal comes from thelens microcomputer 115. In step 1212, the camera microcomputer 208 sendsthe lens microcomputer 115 a request signal to be used for moving thezoom lens group to the tele side. Upon completion of the operation to beperformed in one of the aforementioned steps 1207, 1212 and 1209,control returns to the main routine in step 1213.

Next, processing to be performed by the lens microcomputer 115 of thethird embodiment will be described.

FIG. 16 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. Incidentally, a manual zooming operationwill be described hereunder by way of example. In step 1301, theprocessing is started. Then, in step 1302, the lens microcomputer 115checks whether the zoom stop request signal comes thereto from thecamera microcomputer 208. If the zoom stop request signal has alreadycome thereto, control proceeds to step 1308. Otherwise, control advancesto step 1303 whereupon the lens microcomputer 115 checks from theinformation sent from the camera microcomputer 208 which of the teledirection and the wide direction the moving direction of the zoom lensgroup is. If the tele direction, control proceeds to step 1304.Conversely, if the wide direction, control advances to step 1305.

In step 1304, the lens microcomputer 115 checks whether the zoom lensgroup is positioned at the tele end. If so, control proceeds to step1308. Otherwise, control advances to step 1306. Further, the movingspeed of the zoom lens group and the moving speed and direction of thefocusing lens group are calculated in step 1306. According to a resultof this calculation, the zoom lens group and the focusing lens group aredriven in step 1307. Furthermore, in step 1308, the zoom lens group isstopped.

Upon completion of the operation performed in step 1307 or 1308, thelens microcomputer 115 checks in step 1309 whether the zoom lens groupis placed at the tele end. If so, control proceeds to step 1310.Otherwise, control advances to step 1311. In step 1310, the lensmicrocomputer 115 sets information to be used for sending an electroniczooming permission signal to the camera microcomputer 208. Furthermore,in step 1311, the lens microcomputer 115 sets information to be used forsending an electronic zooming inhibition signal to the cameramicrocomputer 208. Then, control advances to step 1312.

In this step 1312, the lens microcomputer 115 checks whether the zoomlens group is moving to the wide side. If so, control proceeds to step1313. Otherwise, control advances to step 1315. In step 1313, the lensmicrocomputer 115 checks whether a current focal length f of the zoomlens group is not less than a focal length fn at which the zoom lensgroup would reach the tele end within ( 1/60) seconds if the zoom lensgroup moved by maintaining a current zooming speed. If not less than fn,control proceeds to step 1314. Otherwise, control advances to step 1315.In step 1314, the lens microcomputer 115 sets information for sending anelectronic zooming permission signal to the camera microcomputer 208.Furthermore, in step 1315, the lens microcomputer 115 sets informationfor sending an electronic zooming inhibition signal to the cameramicrocomputer 208. Upon completion of the operation to be performed inone of the aforementioned steps 1310, 1314 and 1315, control returns tothe main routine in step 1316.

Next, the case of integrating the processing performed by the lensmicrocomputer 115 with the processing performed by the cameramicrocomputer 208 will be described.

FIG. 18 is a diagram illustrating the timing with which an output videosignal is changed from video signals of an optical zooming region tothose of an electronic zooming region when a zooming operation isperformed from the wide side to the tele side. In this diagram, thetransverse axis represents time. As viewed in this diagram, the righterthe position of a time point on the transverse axis becomes, the latertime the time point indicates. Reference numeral 1101 denotes a rowrepresenting a sequence of fields of a standard television signal.Fields (n−1) to (n+4) are shown in this figure. Reference numeral 1102designates a row showing various kinds of processing to be performed bythe camera microcomputer 208 in the respective fields. Theaforementioned kinds of processing illustrated in FIG. 7 are performedin the respective fields.

Reference numeral 1103 designates a row showing the field Nos. of fieldsin which the input video signals 300 are obtained in the imager 201 byphotoelectric conversion. Incidentally, a field, in which a video signalis read from the imager 201, is immediately subsequent to a field inwhich this video signal is obtained by photoelectric conversion. Thus,the field No. of this field is smaller than the field No. thereof shownin the row 1101 by 1. Reference numeral 1104 designates a row showingthe field No. of a field in which an output signal of the adder 307 isobtained in the imager 201 by photoelectric conversion. However, anoutput signal of the adder 307 is indefinite until a video signal isfetched in the memory circuit 301. After Aa video signal is fetchedthereto, a signal delayed by 1 field is outputted from the adder 307.

Reference numeral 1105 denotes a row indicating which of the input videosignal 300 and the output signal of the adder 307 is selected by theoutput switch circuit 309 according to a switch signal outputted fromthe microcomputer interface circuit 304. Reference numeral 1106designates a row indicating the field No. of a field in which the outputvideo signal 310 is obtained in the imager 201 by photoelectricconversion.

Next, a process flow of the zooming processing will be described byconcentrating on the processing to be performed by the cameramicrocomputer 208.

In the zooming operation from the wide side to the tele side, the lensmicrocomputer 115 detects at the time t(n−1)1 that the current focallength f of the zoom lens group is not less than the focal length fn atwhich the zoom lens group would reach the tele end within ( 1/60)seconds if the zoom lens group moved by maintaining the current zoomingspeed. Then, the lens microcomputer 115 prepares electronic zoomingpermission information for the next communication with the cameramicrocomputer 208 in the field n if the optical zoom lens reaches theoptical tele end at the time t(n)1.

In the field “n”, an electronic zooming enabling signal is sent from thelens microcomputer 115 to the camera microcomputer 208 by thecommunication performed at the time t(n) 1. In the zooming processing atthe time t(n)2, the camera microcomputer 208 performs an operation forcausing the memory circuit 301 to store the input video signal 300 inthe time (n+1). In the field (n+1), an operation for causing the inputvideo signal 300 obtained in the field (n+3) to be stored in the memorycircuit 301 is performed. Moreover, if the optical zoom lens groupreaches the optical tele end at the time t(n)3, the lens microcomputer115 prepares electronic zooming permission information for the nextcommunication with the camera microcomputer 208.

In the field “n”, an electronic zooming preparation permission signal issent from the lens microcomputer 115 to the camera microcomputer 208 bythe communication performed at the time t(n+1)1. In the zoomingprocessing at the time t(n+1)2, the camera microcomputer 208 performs anoperation for causing the memory circuit 301 to store the input videosignal 300 in the time (n+1), and also performs operations of enlargingan image, which is represented by the stored input video signal 300 inthe field (n+2), and of outputting a video signal (n+1)′ representing anenlarged image to the output switch circuit 309, and of selecting areceived output of the adder 307 as an output of the output switchcircuit 309.

In the field (n+2), an operation of storing the input video signal 300,which is obtained in the field (n+3), in the memory circuit 301 isperformed during the zooming processing at the time t(n+2)1. Further,the circuit performs operations of enlarging an image, which isrepresented by the stored input video signal 300 in the field (n+2), inthe field (n+3), and of outputting a video signal (n+1)1 representing anenlarged image, and of selecting a received output of the adder 307 asan output of the output switch circuit 309. Further, the circuitperforms operations of enlarging an image, which is represented by thestored input video signal 300 in the field (n+3), in the field (n+4),and of outputting a video signal (n+1)′ to the output switch circuit309. In the field (n+3) and the subsequent fields, the same processingas performed in the field (n+2) is carried out.

Next, change 1106 in the output video signal 310 with time will bedescribed. Because the zoom lens reaches the optical tele end in thefield “n”, signals obtained in the imager 201 by photoelectricconversion in the fields up to (n−1) and signals obtained byphotoelectric conversion in the field “n”, in which the optical zoomingis ceased in the middle thereof, are video signals obtained during theoptical zooming. Thus, the output video signals outputted in the fieldsup to (n+1) are signals outputted during the optical zooming. Each ofthe output video signals 310 outputted in the field (n+2) and thesubsequent fields are obtained by enlarging the signal stored in thememory circuit 301 in the immediately precedent field and are videosignals obtained during the electronic zooming.

Incidentally, in the aforementioned third embodiment, the lensmicrocomputer 115 is adapted to detect that the current focal length fof the zoom lens group is not less than the focal length fn at which thezoom lens group would reach the tele end within ( 1/60) seconds if thezoom lens group moved by maintaining the current zooming speed. Further,the lens microcomputer 115 is adapted to prepare electronic zoomingpermission information for the next communication with the cameramicrocomputer 208. However, even in the case that a large time delay iscaused in the timing of obtaining electronic zooming permissioninformation from the lens microcomputer 115 by the camera microcomputer208 for some reason after the zoom lens group reaches the optical teleend, smooth switching between optical and electronic zooming operationsis realized by setting fn, which meets the aforementioned inequalityf<fn where f is the focal length of the zoom lens group, in such amanner that the zoom lens group would reach the optical tele end withina time period, which is an integral multiple of the cycle of thecommunication between the lens microcomputer 115 and the cameramicrocomputer 208 corresponding to the aforementioned time delay, if thezoom lens group moved by maintaining the current zooming speed.

As described above, according to the third embodiment, an electroniczooming preparation permission signal and an electronic zooming enablingsignal are outputted to the camera body unit during the zoomingoperation. Thus, even in the case that there is a delay in performingelectronic zooming, a zooming operation is smoothly performed withoutsuspension.

Further, according to the third embodiment, electronic zooming isenabled when the aforementioned signals are inputted from the lens unit.Consequently, even in the case that a delay occurs in performingelectronic zooming, a zooming operation is smoothly performed withoutsuspension.

Fourth Embodiment

In the case that the interchangeable lens unit 100 has anelectrically-controllable optical zooming mechanism, similarly as in thecase of the first to third embodiment, optical zooming and electroniczooming are achieved under the control of the camera microcomputer 208.However, in the case that, as shown in FIGS. 16 and 17, the lens units130 and 140 have no electrically-controllable optical zoomingmechanisms, the control of electronic zooming is not taken intoconsideration.

This fourth embodiment is enabled to smoothly function an electroniczooming mechanism of the camera body unit according to the type of anexternal lens unit (for instance, an interchangeable lens unit),regardless of the presence/absence of an electrically controllableoptical zooming mechanism in the external lens unit.

Hereinafter, the fourth embodiment will be described.

Video camera of the fourth embodiment has a camera body unit whosehardware configuration is the same as that of the body unit 200 shown inFIG. 4. This camera body unit 200 is combined with an interchangeablelens unit that has the same hardware configuration as that of theinterchangeable lens unit shown in FIG. 19, 20 or 4. Incidentally, thefourth embodiment is different in software used in the cameramicrocomputer 208 and the lens microcomputer 115 from the conventionalvideo camera. Hereinafter, only the differences therebetween will bedescribed.

The flow of the processing to be performed by the camera microcomputer208 is broadly similar to the flow illustrated in FIGS. 7 and 8. FIG. 21shows a process flow of step 406 of this embodiment, which isillustrated in FIG. 7.

In step S1401, the processing is started. Then, in step S1402, thecamera microcomputer 208 checks whether the zoom keys 210 and 211 of thecamera body unit 200 are not operated or whether each of these zoom keysis operated in the tele or wide direction. If the zoom keys areoperated, control advances to step S1403. If not operated, controlproceeds to step S1414. In step S1403, the camera microcomputer 208checks manual zooming capability information sent from the lensmicrocomputer 115. If manual zooming is possible, control advances tostep S1414. Otherwise, control proceeds to step S1404 whereupon thecamera microcomputer 208 checks presence-of-zooming-unit informationsent from the lens microcomputer of the interchangeable lens unit. Ifthe lens unit has a zooming unit, control advances to step S1405.Otherwise, control unit proceeds to step S1410. In step S1405, thecamera microcomputer 208 checks whether the zoom keys 210 and 211 of thecamera body unit 200 are operated in a direction corresponding to thetele side. If the zoom keys are operated in a direction corresponding tothe tele side, control advances to step S1406. If the zoom keys areoperated in a direction corresponding to the wide side, control proceedsto step S1409. In step S1406, the camera microcomputer 208 checksoptical tele end information sent from the lens microcomputer of theinterchangeable lens unit. If this information indicates the opticaltele end, control advances to step S1407. Otherwise, control proceeds tostep S1413. In step S1407, the camera microcomputer 208 checks whetherthe zooming unit is at the tele end in the case of electronic zooming.If so, control advances to step S1414. Otherwise, control proceeds tostep S1408. In step S1414, the camera microcomputer 208 checks whetheran electronic zooming operation is currently being performed. If so,control advances to step S1408. Otherwise, control proceeds to stepS1415. In step S1408, an electronic zooming operation is performed byincreasing or decreasing the aforementioned interpolation coefficientsaccording to which of the switches 210 and 211 is pushed. Moreover, thecamera microcomputer 208 controls the enlargement processing circuit 205according to a result of the electronic zooming operation. Then, controladvances to step S1414.

On the other hand, in step S1410, the camera microcomputer 208 checkswhether each of the zoom keys 210 and 211 of the camera body unit 200 isoperated in a direction corresponding to the tele or wide direction. Ifoperated in the direction corresponding to the tele side, controlproceeds to, step S1411. Conversely, if operated in the directioncorresponding to the wide side, control advances to step S1412. In stepS1411, the camera microcomputer 208 checks whether the zooming unit isat the tele end in the case of electronic zooming. If so, controladvances to step S1414. Otherwise, control proceeds to step S1408. Instep S1412, the camera microcomputer 208 checks whether an electroniczooming operation is currently being performed. If so, control advancesto step S1408. Otherwise, control proceeds to step S1414.

In step S1413, the camera microcomputer 208 sets a control signal formoving the zoom lens to the tele side. In step S1414, the cameramicrocomputer 208 sets a control signal for stopping the zoom lens. Instep S1415, the camera microcomputer 208 sets a control signal formoving the zoom lens to the wide side.

Upon completion of the operation performed in one of the aforementionedsteps S1413, S1414 and S1415, control returns to an upper-level routinein step S1416.

Next, the video camera having the combination of the camera body unit200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 130 of the hardware configuration shown inFIG. 19 will be first described below.

As shown in FIG. 19, reference numeral 130 designates an interchangeablelens unit detachably attached to a camera body unit 200. In theinterchangeable lens unit 130, reference numeral 131 denotes a focusinglens group for performing a focusing function; and 132 a variator lensgroup for changing a magnification, which consists of a variator lensand a compensator lens and changes the position thereof in accordancewith a cam (not shown) to thereby vary the focal length thereof.Reference numeral 133 designates a fixed image-forming lens group. Theselens groups 131 to 133 constitute a lens system of what is called afront lens focusing type.

Reference numeral 134 denotes a zoom ring for manually moving thevariator lens group 132 by a cameraman. A zooming operation is enabledonly by using this zoom ring 134 (an optical zooming mechanism whichdoes not operate according to a control signal inputted from an externaldevice). Reference numeral 135 designates a stepping motor for movingthe focusing lens group 131; 136 a zoom encoder; 137 a lensmicrocomputer which is operative to communicate with the microcomputer208 of the camera body unit 200 and to control the stepping motor 135.

FIG. 22 is a flowchart illustrating a part of processing to be performedby the lens microcomputer 137.

In step S1501, the processing is started. Then, in step S1502, the lensmicrocomputer 137 sets presence-of-zooming-unit information and makespreparations for sending this information to the camera microcomputer208. Then, control advances to step S1503 whereupon the lensmicrocomputer 137 sets manual zooming capability information and makespreparations for sending this information to the camera microcomputer208. Subsequently, control proceeds to step S1504 whereupon it is judgedby interruption processing whether the communication between the lensmicrocomputer 137 and the camera microcomputer 208 is completed. Ifcompleted, control advances to step S1505. Otherwise, control goes backto step S1504. In step S1505, the lens microcomputer 137 reads a valueindicated by the zoom encoder 136. Then, control proceeds to step S1506whereupon a driving amount of the focusing lens is calculated from thevalue indicated by the zoom encoder 136 and from an autofocusingestimation value provided by the camera body unit 200 (incidentally, thedetailed description of this value is omitted for simplicity ofdescription). Subsequently, control advances to step S1507 whereupon thestepping motor for moving the focusing lens 131 is driven according tothe driving amount of the focusing lens calculated in step S1506.Thereafter, control goes back to step S1502.

As is understood from the foregoing description, in the case of thecombination of the camera body unit 200 and the interchangeable lensunit 130, the manual zooming capability information (indicating thepresence of the optical zooming mechanism which does not operateaccording to control information provided from an external device) isset (in step S1503) by the lens microcomputer 137. Thus, the cameramicrocomputer 208 judges (in step S1403) that a manual zooming operationcan be performed. Consequently, an electronic zooming mechanism (theenlargement processing circuit 205) provided in the camera body unit 200does not function.

Next, the video camera having the combination of the camera body unit200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 140 of the hardware configuration shown inFIG. 20 will be described below.

As shown in FIG. 20, reference numeral 140 designates an interchangeablelens unit detachably attached to a camera body unit 200. In theinterchangeable lens unit 140, reference numeral 141 denotes a focusinglens group constituting a short focus lens; and 142 a lens microcomputerwhich is operative to communicate with the microcomputer 208 of thecamera body unit 200.

FIG. 23 is a flowchart illustrating a part of processing to be performedby the lens microcomputer 142.

In step S1601, the processing is started. Then, in step S1602, the lensmicrocomputer 142 clears presence-of-zooming-unit information and makespreparations for sending absence-of-zooming-unit information to thecamera microcomputer 208. Then, control advances to step S1603 whereuponthe lens microcomputer 142 sets manual zooming capability informationand makes preparations for sending information, which indicates thatmanual zooming cannot be performed, to the camera microcomputer 208.Subsequently, control proceeds to step S whereupon it is judged byinterruption processing whether the communication between the lensmicrocomputer 142 and the camera microcomputer 208 is completed. Ifcompleted, control goes back to step S1602. Otherwise, control goes backto step S1604.

As is understood from the foregoing description, in the case of thecombination of the camera body unit 200 and the interchangeable lensunit 140, the manual zooming capability information (indicating thepresence of the optical zooming mechanism) is cleared (in step S1602) bythe lens microcomputer 142. Further, the manual zooming capabilityinformation is cleared (in step S1603). Thus, the camera microcomputer208 judges (in steps S1403 and S1404) that a manual zooming operationcannot be performed and no zooming unit is provided in the camera.Consequently, an electronic zooming mechanism (the enlargementprocessing circuit 205) provided in the camera body unit 200 functions.

Next, the video camera having the combination of the camera body unit200 of the hardware configuration and the interchangeable lens unit 100of the hardware configuration, which are shown in FIG. 4, will bedescribed below.

FIG. 24 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. In step S1701, the processing is started.Then, in step S1702, the lens microcomputer 115 checks whether a zoomlens stop request signal (S1414) comes thereto from a cameramicrocomputer 208. If the zoom lens group has already stopped, controlproceeds to step S1708. Otherwise, control advances to step S1703whereupon the lens microcomputer 115 checks according to the informationsent by the camera microcomputer 208 which of the tele direction and thewide direction the moving direction of the zoom lens group is. If themoving direction of the zoom lens group is the tele direction, controlproceeds to step S1704. If the wide direction, control advances to stepS1705.

In step S1704, the lens microcomputer 115 checks whether the zoom lensgroup is positioned at the tele end. If so, control proceeds to stepS1708. Otherwise, control advances to step S1706. Further, in stepS1705, the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step S1708.Otherwise, control advances to step S1706. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step S1706. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in stepS1707. Furthermore, in step S1708, the zoom lens group is stopped.

Upon completion of the operation performed in step S1707 or S1708, thelens microcomputer 115 checks in step S1709 whether the zoom lens groupis placed at the tele end. If so, control proceeds to step S1710.Otherwise, control advances to step S1711. In step S1710, the lensmicrocomputer 115 sets optical tele end information and makespreparations for sending this information to the camera microcomputer208. Further, in step S1711, the lens microcomputer 115 clears opticaltele end information and makes preparations for sending information,which indicates that the zoom lens group is not placed at the tele end,to the camera microcomputer 208. In step S1712, the lens microcomputer115 sets presence-of-zooming-unit information and makes preparations forsending this information to the camera microcomputer 208. Then, controlproceeds to step S1713 whereupon the lens microcomputer 115 clearsmanual zooming capability information and makes preparations for sendinginformation, which indicates that manual zooming cannot be performed, tothe camera microcomputer 208. Subsequently, control advances to stepS1714. Further, control returns to a main routine in step S1714.

As is understood from the foregoing description, in the case of thecombination of the camera body unit 200 and the interchangeable lensunit 100, the presence-of-zooming-unit information is set (in stepS1712) by the lens microcomputer 115. Further, the manual zoomingcapability information is cleared (in step S1713). Thus, the cameramicrocomputer 208 judges (in steps S1403 and S1404) that a manualzooming operation cannot be performed and a zooming unit is provided inthe camera. Consequently, an electronic zooming mechanism provided inthe camera body unit 200 functions.

Fifth Embodiment

A video camera of the fifth embodiment has a camera body unit of thesame hardware configuration as the configuration of the unit 200illustrated in FIG. 4, similarly as the fourth embodiment does. In thecase of the fifth embodiment, such a camera body unit is combined withan interchangeable lens unit of the same hardware configuration as theconfiguration of the interchangeable lens unit shown in FIG. 19, 20 or4. Incidentally, the fifth embodiment is different in software used inthe camera microcomputer 208 and the lens microcomputer 115 from theconventional video camera and the fourth embodiment. Hereunder, only thedifferences therebetween will be described.

The flow of the processing to be performed by the camera microcomputer208 of this embodiment is broadly similar to the flow illustrated inFIGS. 7 and 8. FIG. 25 shows a process flow of step 406 of thisembodiment, which is illustrated in FIG. 7.

In step S1801, the processing is started. Then, in step S1802, thecamera microcomputer 208 checks whether the zoom keys 210 and 211 of thecamera body unit 200 are not operated or whether each of these zoom keysis operated in the tele or wide direction. If the zoom keys areoperated, control advances to step S1803. If not operated, controlproceeds to step S1814. In step S1803, the camera microcomputer 208checks specific lens group information sent from the lens microcomputerof the interchangeable lens unit. If the interchangeable lens unitbelongs to the specific lens group, control advances to step S1414.Otherwise, control proceeds to step S1804 whereupon the cameramicrocomputer 208 checks presence-of-zooming-unit information sent fromthe lens microcomputer of the interchangeable lens unit. If the lensunit has a zooming unit, control advances to step S1805. Otherwise,control unit proceeds to step S1810. In step S1805, the cameramicrocomputer 208 checks whether the zoom keys 210 and 211 of the camerabody unit 200 are operated in a direction corresponding to the teleside. If the zoom keys are operated in a direction corresponding to thetele side, control advances to step S1806. If the zoom keys are operatedin a direction corresponding to the wide side, control proceeds to stepS1809. In step S1806, the camera microcomputer 208 checks optical teleend information sent from the lens microcomputer of the interchangeablelens unit. If this information indicates the optical tele end, controladvances to step S1807. Otherwise, control proceeds to step S1813. Instep S1807, the camera microcomputer 208 checks whether the zooming unitis at the tele end in the case of electronic zooming. If so, controladvances to step S1814. Otherwise, control proceeds to step S1808. Instep S1809, the camera microcomputer 208 checks whether an electroniczooming operation is currently being performed. If so, control advancesto step S1808. Otherwise, control proceeds to step S1815. In step S1808,an electronic zooming operation is performed by increasing or decreasingthe aforementioned interpolation coefficients according to which of theswitches 210 and 211 is pushed. Moreover, the camera microcomputer 208controls the enlargement processing circuit 205 according to a result ofthe electronic zooming operation. Then, control advances to step S1814.

On the other hand, in step S1810, the camera microcomputer 208 checkswhether each of the zoom keys 210 and 211 of the camera body unit 200 isoperated in a direction corresponding to the tele or wide direction. Ifoperated in the direction corresponding to the tele side, controlproceeds to step S1811. Conversely, if operated in the directioncorresponding to the wide side, control advances to step S1812. In stepS1811, the camera microcomputer 208 checks whether the zooming unit isat the tele end in the case of electronic zooming. If so, controladvances to step S1814. Otherwise, control proceeds to step S1808. Instep S1812, the camera microcomputer 208 checks whether an electroniczooming operation is currently being performed. If so, control advancesto step S1808. Otherwise, control proceeds to step S1814.

In step S1813, the camera microcomputer 208 sets a control signal formoving the zoom lens group to the, tele side. In step S1814, the cameramicrocomputer 208 sets a control signal for stopping the zoom lens. Instep S11815, the camera microcomputer 208 sets a control signal formoving the zoom lens to the wide side.

Upon completion of the operation performed in one of the aforementionedsteps S1813, S1814 and S1815, control returns to an upper-level routinein step S1816.

Next, the video camera having the combination of the camera body unit200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 130 of the hardware configuration shown inFIG. 19 will be first described below. It is assumed that theinterchangeable lens unit 130 has a manual zooming mechanism whichcannot be controlled by using a control signal inputted from an externaldevice, and that the lens unit 130 belongs to the “specific lens group”.

FIG. 26 is a flowchart illustrating a part of processing to be performedby the lens microcomputer 137.

In step S1901, the processing is started. Then, in step S1902, the lensmicrocomputer 137 sets presence-of-zooming-unit information and makespreparations for sending this information to the camera microcomputer208. Then, control advances to step S1903 whereupon the lensmicrocomputer 137 sets specific lens group information and makespreparations for sending this information to the camera microcomputer208. Subsequently, control proceeds to step S1904 whereupon it is judgedby interruption processing whether the communication between the lensmicrocomputer 137 and the camera microcomputer 208 is completed. Ifcompleted, control advances to step S1905. Otherwise, control goes backto step S1904. In step S1905, the lens microcomputer 137 reads a valueindicated by the zoom encoder 136. Then, control proceeds to step S1906whereupon a driving amount of the focusing lens is calculated from thevalue indicated by the zoom encoder 136 and from an autofocusingestimation value provided by the camera body unit 200 (incidentally, thedetailed description of this value is omitted for simplicity ofdescription). Subsequently, control advances to step S1907 whereupon thestepping motor for moving the focusing lens 131 is driven according tothe driving amount of the focusing lens calculated in step S1906.Thereafter, control goes back to step S1902.

As is understood from the foregoing description, in the case of thecombination of the camera body unit 200 and the interchangeable lensunit 130, the specific lens group information (indicating that the lensunit has an optical zooming mechanism which does not operate accordingto control information provided from an external device) is set (in stepS1903) by the lens microcomputer 137. Thus, the camera microcomputer 208judges (in step S1903) that the lens unit is a specific lens group.Consequently, an electronic zooming mechanism (the enlargementprocessing circuit 205) provided in the camera body unit 200 does notfunction.

Next, the video camera having the combination of the camera body unit200 of the hardware configuration shown in FIG. 4 and theinterchangeable lens unit 140 of the hardware configuration shown inFIG. 20 will be described below. Incidentally, it is assumed that theinterchangeable lens unit 140 does not have a zooming mechanism and thusdoes not belong to the “specific lens group”.

FIG. 27 is a flowchart illustrating a part of processing to be performedby the lens microcomputer 142.

In step S2001, the processing is started. Then, in step S2002, the lensmicrocomputer 142 clears presence-of-zooming-unit information and makespreparations for sending absence-of-zooming-unit information to thecamera microcomputer 208. Then, control advances to step S2003 whereuponthe lens microcomputer 142 clears specific lens group information andmakes preparations for sending information, which indicates that thelens unit does not belong to the specific lens group, to the cameramicrocomputer 208. Subsequently, control proceeds to step S2004whereupon it is judged by interruption processing whether thecommunication between the lens microcomputer 142 and the cameramicrocomputer 208 is completed. If completed, control goes back to stepS2002. Otherwise, control goes back to step S2004.

As is understood from the foregoing description, in the case of thecombination of the camera body unit 200 and the interchangeable lensunit 140, the absence-of-zooming-unit information is set by the lensmicrocomputer 142. Further, the specific lens group information iscleared (in steps S2002 and S2003). Thus, the camera microcomputer 208judges (in steps S1803 and S1804) that the lens unit is not a specificlens group and no zooming unit is provided in the camera. Consequently,an electronic zooming mechanism (the enlargement processing circuit 205)provided in the camera body unit 200 functions.

Next, the video camera having the combination of the camera body unit200 of the hardware configuration and the interchangeable lens unit 100of the hardware configuration, which are shown in FIG. 4, will bedescribed below. Incidentally, it is assumed that the interchangeablelens unit 100 does not have a manual zooming mechanism which cannot becontrolled by a control signal inputted from an external device and thatthe lens unit 100 does not the “specific lens group”.

FIG. 28 is a flowchart illustrating processing concerning a zoomingoperation, which is a part of the entire processing to be performed bythe lens microcomputer 115. In step S2101, the processing is started.Then, in step S2102, the lens microcomputer 115 checks whether the zoomlens stop request signal comes thereto from a camera microcomputer 208.If the zoom lens group has already stopped, control proceeds to stepS2108. Otherwise, control advances to step S2103 whereupon the lensmicrocomputer 115 checks according to the information sent by the cameramicrocomputer 208 which of the tele direction and the wide direction themoving direction of the zoom lens group is. If the moving direction ofthe zoom lens group is the tele direction, control proceeds to stepS2104. If the wide direction, control advances to step S2105.

In step S2104, the lens microcomputer 115 checks whether the zoom lensgroup is positioned at the tele end. If so, control proceeds to stepS2108. Otherwise, control advances to step S2106. Further, in stepS2105, the lens microcomputer 115 checks whether the zoom lens group ispositioned at the wide end. If so, control proceeds to step S2108.Otherwise, control advances to step S2106. The moving speed of the zoomlens group and the moving speed and direction of the focusing lens groupare calculated in step S2106. According to a result of this calculation,the zoom lens group and the focusing lens group are driven in stepS2107. Furthermore, in step S2108, the zoom lens group is stopped.

Upon completion of the operation performed in step S2107 or S2108, thelens microcomputer 115 checks in step S2109 whether the zoom lens groupis placed at the tele end. If so, control proceeds to step S2110.Otherwise, control advances to step S2111. In step S2110, the lensmicrocomputer 115 sets optical tele end information and makespreparations for sending this information to the camera microcomputer208. Further, in step S2111, the lens microcomputer 115 clears opticaltele end information and makes preparations for sending information,which indicates that the zoom lens group is not placed at the tele end,to the camera microcomputer 208. In step S2112, the lens microcomputer115 sets presence-of-zooming-unit information and makes preparations forsending this information to the camera microcomputer 208. Then, controlproceeds to step S2113 whereupon the lens microcomputer 115 clearsspecific lens group information and makes preparations for sendinginformation, which indicates that the lens unit does not belong to thespecific lens group, to the camera microcomputer 208. Subsequently,control advances to step S2114. Further, control returns to a mainroutine in step S2114.

As is understood from the foregoing description, in the case of thecombination of the camera body unit 200 and the interchangeable lensunit 100, the presence-of-zooming-unit information is set (in stepS2112) by the lens microcomputer 115. Further, the specific lens groupinformation is cleared (in step S2113). Thus, the camera microcomputer208 judges (in steps S1803 and S1804) that the lens unit is not aspecific lens group and a zooming unit is provided in the camera.Consequently, an electronic zooming mechanism provided in the camerabody unit 200 functions.

Incidentally, in the foregoing description of the fourth and fifthembodiments, it has been described that these embodiments are adapted todetect the zoom operating direction (namely, detect that the zoom lensgroup is operated toward the tele side or toward the wide side).However, the present invention is easily applied to a case that thecamera has multi-zooming-speed in each zoom operating direction.

Further, even in the case that the camera body unit has a plurality ofzoom operating means or that an external input device, such as a remotecontrol device, for a camera body unit has zoom lens operating means,the present invention is easily applied to such a case by handling thesemeans as a single zoom operating means in the camera body unit.

Moreover, in the foregoing description of the fifth embodiment, thespecific lens group has been defined as a lens group having an opticallens group that cannot be controlled by a control signal inputted froman external device. However, it is apparent that other requirements,such as performance, price and use of the interchangeable lens unit, maybe employed as the requirements for the specific lens group. Any of suchrequirements may be applied to the processing performed in the camerabody unit, in view of consistency between such a requirement and theperformance of or the manner of use of the electronic zooming function.

As described above, according to the fourth and fifth embodiments, anelectronic zooming mechanism of the camera body unit smoothly functionsaccording to the type of an external lens unit (for instance, aninterchangeable lens unit), regardless of the presence/absence of anelectrically controllable optical zooming mechanism in the external lensunit.

As many apparently widely different embodiments of the present inventioncan be made without departing from-the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the claims.

1. An image capturing apparatus detachably mounting a lens unit whichhas a first zoom operation unit for instructing a zooming operation andan optical zoom mechanism, comprising: an image capturing unit; a secondzoom operation unit configured to instruct the zooming operation; anelectronic zoom unit configured to enlarge an image captured by saidimage capturing unit; an information input unit configured to input zoominformation which is stored in the lens unit and indicates whether theoptical zoom mechanism is a first optical zoom mechanism that operatesin response to a control signal from said second zoom operation unit ora second optical zoom mechanism that does not operate in response to acontrol signal from said second zoom operation unit; and a control unitconfigured to change a control of the optical zoom mechanism based onoperation information of said first zoom operation unit, operationinformation of said second zoom operation unit, and information ofwhether or not the enlarging operation of the image is performed by saidelectronic zoom unit, wherein said electronic zoom unit enlarges theimage captured by said image capturing unit in any case that the zoominformation indicates that the optical zoom mechanism is the firstoptical zoom mechanism or the zoom information indicates that theoptical zoom mechanism is none of the first and second optical zoommechanism.
 2. The apparatus according to claim 1, wherein theinformation used by said control unit includes at least one of adirection of zooming, a speed of zooming, and both of the direction andthe speed of zooming.
 3. A lens unit which is detachably mounted to animage capturing apparatus having an image capturing unit, a second zoomoperation unit for instructing a zooming operation, and an electroniczoom unit for enlarging an image captured by the image capturing unit,comprising: an optical zoom mechanism; a first zoom operation unitconfigured to instruct the zooming operation; an information output unitconfigured to output zoom information which is stored in the lens unitand indicates whether the optical zoom mechanism is a first optical zoommechanism that operates in response to a control signal from the secondzoom operation unit or a second optical zoom mechanism that does notoperate in response to a control signal from the second zoom operationunit; and an information input unit configured to input informationcalculated in the image capturing apparatus based on operationinformation of said first zoom operation unit, operation information ofthe second zoom operation unit, and information of whether or not theenlarging operation of the image is performed by the electronic zoomunit, wherein said optical zoom mechanism is controlled based on theinformation which is calculated in the image capturing apparatus and isinput by said information input unit.
 4. The lens unit according toclaim 3, wherein the information input by said information input unitincludes at least one of a direction of zooming, a speed of zooming, andboth of the direction and the speed of zooming.